Nothing looks quite like natural stone for a countertop. The glossy surface, the play of color, the intricate patterns, but what’s the story behind the aesthetics of these beautiful stone countertops?
Granite is a common rock and frequently used for countertops. It’s an intrusive igneous rock, meaning it cooled from magma (underground lava) deep below the earth’s surface. Like all rocks, it is comprised of minerals. The essential minerals that make granite are feldspars, quartz, mica and amphibole. Our Venetian Gold is a good example of the classic pink hued granite most people think of. But granite can contain accessory minerals which result in widely different colors. Granite takes a very long time form. Magma that is several miles underground doesn’t cool off quickly. During this slow cooling (it really depends- hundreds of years, possibly millions) mineral crystals form. The slower the cooling, the bigger the crystals. Much of the earth’s granite formed in the Precambrian period which ended about 550 million years ago. That’s a fun fact to tell guests as they admire the looks of your new stone countertops.
Marble is another popular countertop option. Unlike granite, marble is, geologically speaking, a metamorphic rock and forms when limestone is subjected to high temperature and pressure. Masons sometimes use “marble” to describe a variety of rocks but the genuine article is always metamorphic. Marble can be found in areas that have experienced lots of tectonic activity at some point in the past. The heat and pressure necessary to transform limestone to marble can occur when limestone is driven deep into the earth’s crust or when it is compressed, such as when two tectonic plates crash into each other. It’s rather flattering to think that heat and pressure so intense that it causes solid rock to become pliable and recrystallize, usually in the process of building a mountain range, is what went into the creation of your stone countertops.
Limestone is another option. Limestone is found all over the world and is a sedimentary rock that forms from the very small exoskeletons of ocean-dwelling crustaceans and similar animals. As these tiny, calcium carbonate-rich exoskeletons (think crab shells) settle on the ocean floor, they form a “marine mud.” This mud builds in layers and over millions of years, as ocean basins shift and drain, some of these mud regions dry up and harden like cement, becoming limestone. Much of the lamination observable in limestone, such as Limestone Gibraltar, are the preserved bedding planes of the original ocean bottom. Looking at a fossilized sea floor ranging from several tens of millions to a few hundred million years old every time you head into the kitchen makes for a rather profound experience.